There is a steadily increasing number of wireless systems and applications. It is desirable in these systems to have highly efficient transceiver structures, which can be used for multimode purposes, such as GSM/UMTS (Global System for Mobile communications/Universal Mobile Telecommunications System). In addition, WLAN and Bluetooth are being provided as applications in mobile phones, and are being provided together on the same silicon in so called “combo” solutions. “WLAN”, as used herein, refers to a wireless local area network, such as a network meeting the IEEE 802.11b (i.e., “Wi-Fi”) or IEEE 802.11g standard. Bluetooth is mainly directed towards low-power, short-range applications, and WLAN typically provides greater range and bandwidth, but higher power consumption. WLAN and Bluetooth operate in the same 2.4 GHz ISM (Industrial-Scientific-Medical) frequency band. This makes it possible to share front-end components (e.g., antenna, power amplifier, switch, filter, etc.) between the WLAN and Bluetooth applications.
In a device having a combination of WLAN and Bluetooth applications, there may be a limited number of operation scenarios. For example, both applications may not be able to transmit at the same time, and one application may not be able to receive while the other application is transmitting. Allowed operation scenarios include transmitting with one application at a time, and both applications receiving at the same time. These operation scenarios make it possible to share main parts of the transmitter for both applications.
Devices that provide WLAN capabilities typically use an IQ (In-phase-Quadrature) modulator structure for the WLAN communications. An IQ modulator is also referred to as a quadrature modulator. Devices that provide Bluetooth capabilities typically use a polar modulator for the Bluetooth communications. For devices having a combination of WLAN and Bluetooth applications, a conventional IQ modulator is typically modified or reconfigured to support both applications. However, using a pure IQ modulator for both applications is not an optimum solution as it is more appropriate for a broader band system, such as WLAN, rather than a narrower band system, such as Bluetooth.
For these and other reasons, there is a need for the present invention.